On Wed, Sep 02, 2026 at 04:15:17PM +0100, Lorenzo Stoakes (ARM) wrote: > On Wed, Sep 02, 2026 at 01:09:35PM +0100, Yeoreum Yun wrote: > > There're some random failure for split_huge_page_test when khugepaged > > collapses pages into pmd again which had split by the test. > > > > Prevent the khugepaged's collapses for split page by setting the > > mapped pmd-huge-page with MADV_NOHUGEPAGE before split. > > Maybe worth saying that MADV_NOHUGEPAGE doesn't immediately split anything, > just > prevents future khugepaged collapses? > > > > > Suggested-by: Kevin Brodsky <[email protected]> > > Suggested-by: Lorenzo Stoakes (ARM) <[email protected]> > > Signed-off-by: Yeoreum Yun <[email protected]> > > LGTM, thanks, with a few nits above/below (sorry! :P) > > Reviewed-by: Lorenzo Stoakes (ARM) <[email protected]> > > > --- > > tools/testing/selftests/mm/split_huge_page_test.c | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > > > diff --git a/tools/testing/selftests/mm/split_huge_page_test.c > > b/tools/testing/selftests/mm/split_huge_page_test.c > > index 86a603692826..4bbad892bc57 100644 > > --- a/tools/testing/selftests/mm/split_huge_page_test.c > > +++ b/tools/testing/selftests/mm/split_huge_page_test.c > > @@ -168,6 +168,14 @@ static char *allocate_zero_filled_hugepage(size_t len) > > return result; > > } > > > > +static void madv_nohuge(void *addr, size_t len) > > Maybe call it disable_khugepaged() to make it explicit that's what this is > doing > rather than eliminating any THP pages in the range? > > > +{ > > Maybe a comment here like: > > /* > * Disables khugepaged from collapsing THPs in range, existing THP > * pages remain. > */
Okay :) I'll modify in the next-round. Thanks! [...] -- Sincerely, Yeoreum Yun
